JP2006030837A - Antireflective lamination film and display medium using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antireflective lamination film which is excellent in all of transparency, surface hardness, scratch resistance and static resistance and is capable of suppressing color irregularity with satisfactory productivity. <P>SOLUTION: The antireflective lamination film is constituted by laminating a hard coat layer, a conductive layer and a low refractive index layer having a refractive index lower than that of the conductive layer in this order on a transparent substrate. Therein, the conductive layer includes an organic silicon compound presented by the following formula or its hydrolysate; (RO)<SB>3</SB>Si-(CH<SB>2</SB>)<SB>n</SB>-Si(OR)<SB>3</SB>, wherein R denotes an alkyl group and n is an integer (1≤n≤8). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is excellent in productivity, optical characteristics, antistatic properties, surface hardness and scratch resistance, and is applied to, for example, a display screen of a display (liquid crystal display, CRT display, projection display, plasma display, EL display, etc.). The present invention relates to an antireflection laminated film.

  Many displays are used in an environment where external light or the like enters regardless of whether indoors or outdoors. Incident light such as external light is specularly reflected on the display surface or the like, and the reflected image is mixed with display light to lower the display quality and make the display image difficult to see. For this reason, in order to provide an antireflection function, a multilayer film (antireflection film) having an antireflection layer made of a transparent thin film of metal oxide has been conventionally used. Here, the transparent thin film of metal oxide is formed by a chemical vapor deposition (CVD) method or a physical vapor deposition (PVD) method, and is formed in particular by a vacuum vapor deposition method which is a physical vapor deposition method. The antireflection film thus formed exhibits excellent optical characteristics, but the formation method by vapor deposition has a problem that productivity is low and it is not suitable for mass production.

  In addition, in the antireflection multilayer film used for the display surface, since the surface is relatively flexible, in order to impart surface hardness, a hard coat layer made of a polymer of an acrylic polyfunctional compound is provided on the display surface, A method of forming an antireflection layer thereon is performed. The hard coat layer has high surface hardness, glossiness, transparency, and scratch resistance, which are unique properties of acrylic resin, but it has high insulating properties, so it is easy to be charged and applied to the product surface provided with the hard coat layer. There have been problems such as dirt caused by adhesion of dust and the like, and troubles caused by charging when used in precision machines.

  Therefore, in order to prevent charging, a hard coat kneading method (for example, refer to Patent Document 1) in which a conductive agent is kneaded into the hard coat layer, or between the substrate and the hard coat layer or between the hard coat layer and the antireflection layer. In the meantime, a method of providing a conductive layer very thinly so as not to reduce the surface hardness is used (for example, see Patent Documents 2 and 3). Moreover, the coating method is used as the formation method, and the improvement of productivity is attempted.

  At this time, in the method of providing a conductive layer between the layers, it is necessary to control the refractive index and film thickness of each layer in order to control optical interference in order to prevent color unevenness in the laminated film.

  When providing a conductive layer between layers, a conductive layer mainly made of a binder (acrylic binder) made of an acrylic resin and a conductive agent is used (for example, see Patent Document 2).

The patent literature is as follows.
JP-A-11-92750 JP-A-11-326602 JP 2001-255403 A

  However, in the method of kneading the conductive agent in the hard coat layer, a large amount of electron conductive fine particles must be used in order to sufficiently exhibit the conductivity, and as a result, the light transmittance of the hard coat layer is lowered. Problem has occurred. On the other hand, in order to increase the light transmittance without reducing the blending amount of the conductive agent, when reducing the film thickness of the hard coat layer kneaded with the conductive agent, in the laminated film having such a hard coat layer, the surface hardness, There was a problem that the substrate protection function such as scratch resistance was deteriorated.

  In the method of providing a conductive layer between layers, it is difficult to control the film thickness of each layer in the coating method. Although the refractive index can be controlled by the vacuum deposition method, the productivity is poor.

  In addition, when the conductive layer is formed using an acrylic binder, the film strength decreases as the thickness of the conductive layer increases, the adhesion between the conductive layer and the antireflection layer becomes insufficient, and the surface hardness of the entire laminated film There was a problem that the scratch resistance and the like were poor. On the other hand, if a conductive layer is provided between the base material and the hard coat layer, the problem of poor adhesion can be avoided. However, since sufficient conductivity is difficult to be exhibited, the hard coat is considered in consideration of conductivity. It was necessary to perform special treatments such as plating and addition of fine particles on the layer, which made the manufacturing process more complicated.

  The present invention has been made in order to solve the above-mentioned problems, and provides an antireflection laminate film with excellent productivity, transparency, surface hardness, scratch resistance, and antistatic properties, and suppressed color unevenness with high productivity. For the purpose.

In the first aspect of the present invention, a hard coat layer, a conductive layer, and a low refractive index layer having a lower refractive index than the conductive layer are laminated in this order on a transparent support, and the conductive layer is (RO) ₃ Si. — (CH ₂ ) _n —Si (OR) ₃ (wherein R represents an alkyl group, n is an integer (1 ≦ n ≦ 8)) (hereinafter referred to as Chemical Formula 1) An antireflection laminated film comprising a compound or a hydrolyzate thereof is provided.

  The present invention according to claim 2 provides the antireflection laminated film according to claim 1, wherein the conductive layer further contains inorganic fine particles having a particle diameter of 1 to 100 nm as a refractive index adjusting agent. .

  The present invention according to claim 3 provides the antireflection laminated film according to claim 1 or 2, wherein the refractive index adjusting agent is antimony pentoxide fine particles.

  The present invention according to claim 4 provides the antireflection laminated film according to any one of claims 1 to 3, wherein the low refractive index layer has a matrix containing silicon alkoxide or a hydrolyzate thereof. Is.

  The present invention according to claim 5 is characterized in that the difference between the refractive index of the hard coat layer and the refractive index of the conductive layer is 4% or less. A film is provided.

  In the present invention according to claim 6, the conductive layer is nd = λ / 4 (where n is the refractive index of the layer, d is the layer thickness, λ is the wavelength of light, and 500 ≦ λ ≦ 900 is satisfied. It is an integer) (hereinafter referred to as Formula 2). The antireflection laminated film according to claim 1 is provided.

  The present invention according to claim 7 provides a display medium characterized in that the antireflection laminated film according to any one of claims 1 to 6 is used on the front surface of the display medium.

The inorganic fine particles having a particle diameter of 1 to 100 nm, which is a refractive index adjusting agent, include at least one of Al ₂ O ₃ , TiO ₂ , ATO, ITO, Sb ₂ O ₅ , SnO ₂ , WO ₂ and ZrO _2. It is preferable to contain.

The low-refractive index layer is R _y Si (OR) _4-y (wherein R represents an alkyl group and x is an integer satisfying 0 ≦ y ≦ 4) (hereinafter referred to as Chemical Formula 2) It is preferable to contain the matrix resin containing the hydrolyzate of the silicon alkoxide shown by this.

Here, the low refractive index layer is R ″ _z Si (OR) _4−z (where R ″ is a non-reactive functional group having an alkyl group, a fluoroalkyl group or a fluoroalkylene oxide group at the terminal). Z is an integer satisfying 1 ≦ z ≦ 3) (hereinafter referred to as Chemical Formula 3), and preferably further containing a hydrolyzate of silicon alkoxide.

  The low refractive index layer has n′d ′ = λ / 4 (where n ′ is the refractive index of the antireflection layer, d ′ is the thickness of the antireflection layer, λ is the wavelength of light (nm)), and 500 ≦ λ ≦ 600) (hereinafter referred to as Equation 6).

  In addition, the display medium of the present invention preferably includes a polarizing plate.

  ADVANTAGE OF THE INVENTION According to this invention, it is excellent in all of transparency, surface hardness, abrasion resistance, and antistatic property, and can provide the antireflection laminated film in which the color nonuniformity was suppressed with sufficient productivity.

  The antireflection laminated film of the present invention will be described below using an example having a transparent support, a hard coat layer, a conductive layer, and an antireflection layer.

  For example, as shown in FIG. 1, a hard coat layer 2, a conductive layer 3, and an antireflection layer 4 are laminated on the transparent support 1 in this order to form an antireflection laminated film 5. it can.

  In the antireflection laminated film of the present invention, it is preferable that a transparent support, a conductive layer, a hard coat layer, and an antireflection layer are laminated in this order.

  Further, the conductive layer is made of a matrix resin containing an organosilicon compound represented by the chemical formula 1, and may contain inorganic fine particles having a particle diameter of 1 to 100 nm as a refractive index adjuster.

  Since the matrix resin contains the above organosilicon compound, the adhesion between the conductive layer and the hard coat layer or the antireflection layer is excellent, so that the support and the hard coat layer are not peeled off between the layers. In addition, the conductive layer and the antireflection layer can be stacked in this order.

  In the present invention, as described above, the transparent support, the hard coat layer, the conductive layer, and the antireflection layer are preferably laminated in this order.

  Accordingly, when the antireflection laminated film of the present invention is installed on an article such as a display and the support is placed on the article side, or the substrate constituting the display is used instead of the support, the conductive layer is applied to the article. Thus, it is possible to take a form located outside the hard coat layer, and to efficiently exhibit antistatic properties.

  Further, since the conductive layer functions to prevent static charge, it is not necessary to add a conductive agent or the like to the hard coat layer, and the thickness of the hard coat layer can be arbitrarily set without impairing transparency. Thus, it is possible to satisfactorily retain the substrate protection function derived from the above, for example, surface hardness and scratch resistance.

  Here, the organic silicon compound may be any compound represented by Chemical Formula 1. Examples include bis-trimethoxysilyl-ethane, bis-trimethoxysilyl-methane, bis-trimethoxysilyl-hexane, and the like.

  Furthermore, in the matrix resin, even if a hydrolyzate of silicon alkoxide represented by Chemical Formula 2 is added, there is no problem in conductivity, adhesion and strength.

Examples of the inorganic fine particles include oxide fine particles, electron conductive fine particles, and ion conductive fine particles. The oxide fine particles are for adjusting the refractive index, and examples thereof include Al ₂ O ₃ , TiO ₂ , SnO ₂ , and ZrO ₂ . Examples of the electron conductive fine particles include antimony oxide doped tin oxide (ATO) and tin oxide doped indium oxide (ITO).

  Examples of the ion conductive fine particles include fine particles composed of antimony pentoxide (antimony pentoxide fine particles), tungsten oxide fine particles, and the like.

  In the conductive layer, it is preferable to use ion conductive fine particles as the inorganic particles.

  Since the ion conductive fine particles can exhibit conductivity in a relatively low density distribution state, by using the ion conductive fine particles, while maintaining the transparency of the conductive layer very well, and the film of the conductive layer Sufficient conductivity can be exhibited while arbitrarily controlling the thickness so as to satisfy Equation 2 described later. In addition, since the content of the ion conductive fine particles in the conductive layer can be arbitrarily controlled within a range where the conductivity is expressed, the refractive index of the conductive layer can be easily controlled, and the refractive index of the conductive layer. Can be made close to the refractive index of the hard coat layer to suppress optical interference between these layers. Therefore, color unevenness can be prevented more stably. Note that the refractive index of the conductive layer can be controlled by increasing the refractive index of the conductive layer as the content of the ion conductive fine particles in the conductive layer is higher, for example.

  It is preferable to use antimony pentoxide fine particles as the ion conductive fine particles.

  Antimony pentoxide is an ion-conductive substance and has crystal water, so it has a small amount compared to electron conductive fine particles such as antimony oxide-doped tin oxide (ATO) and tin oxide-doped indium oxide (ITO). It exhibits conductivity and is not easily affected by the humidity environment. Therefore, permanent conductivity can be expressed in the antireflection laminated film.

  In addition, by using antimony pentoxide fine particles (refractive index 1.64), which is a material having a relatively lower refractive index than other metal oxides, and controlling the content thereof, the refractive index of the conductive layer can be controlled over a wide range. This can be performed particularly accurately, and the refractive index of the conductive layer can be made close to the refractive index of the hard coat layer. That is, light interference between the hard coat layer and the conductive layer can be stably suppressed, and color unevenness can be more easily prevented in the antireflection laminated film.

Although there is no restriction | limiting in particular in content of electroconductive fine particle, From the surface of electroconductivity expression and the refractive index adjustment of a conductive layer, the range of 20-80 mass% with respect to 100 mass% of electroconductive fine particles and matrix resin total. The range of 30 to 70% by mass is more preferable in terms of the balance between conductivity and layer strength. Further, in order to improve the dispersibility of the conductive fine particles in the matrix resin, a dispersant can be added to the matrix resin. There is no restriction | limiting in particular as a dispersing agent, It is preferable to use a silicone type dispersing agent.

  In the antireflection laminated film of the present invention, the difference between the refractive index of the hard coat layer and the refractive index of the conductive layer is 4% or less.

  Thereby, it is possible to prevent the occurrence of color unevenness in the antireflection laminated film due to optical interference between layers.

  Further, the conductive layer has nd = λ / 4 (where n is the refractive index of the conductive layer, d is the thickness of the conductive layer, λ is the wavelength of light (nm), and is a number satisfying 500 ≦ λ ≦ 900. There is (formula 2). For example, the length d shown in FIG. 1 is d = λ / 4n (where n is the refractive index of the conductive layer, d is the thickness of the conductive layer, λ is the wavelength of light (nm), and 500 ≦ λ ≦ 900).

  When the film thickness of the conductive layer satisfies Equation 2, the spectral reflectance of the luminous reflection region of the antireflection laminate film exhibits a reflectance curve close to flat, thereby providing an antireflection laminate film having no color. can do. In particular, the reflectance curve is flat over a wide wavelength region of the visible light wavelength, so even if the film thickness varies slightly during the manufacturing stage, color unevenness is less likely to occur and the film thickness can be controlled more than by vacuum evaporation. Even with a difficult coating method, it is possible to stably provide an antireflection laminated film having no color. That is, an antireflection laminated film having no color (no color unevenness) can be produced with high productivity.

  As described above, according to the present invention, color unevenness is suppressed while maintaining the surface hardness, scratch resistance, and antistatic property of the antireflection laminated film, that is, while maintaining the base material protecting function and antistatic property. can do.

  In the antireflection laminated film of the present invention, as the transparent support, films or sheets made of various organic polymers can be used. For example, a base material usually used for an optical member such as a display can be cited, considering optical properties such as transparency and refractive index of light, and further various physical properties such as impact resistance, heat resistance and durability, Polyolefin type (polyethylene, polypropylene, etc.), polyester type (polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, etc.), cellulose type (triacetyl cellulose, diacetyl cellulose, cellophane, etc.), polamide type (nylon-6, nylon-66, etc.) ), Acrylic (polymethyl methacrylate, etc.), polystyrene, polyvinyl chloride, polyimide, polyvinyl alcohol, polycarbonate, ethylene vinyl alcohol, or other organic polymer. In particular, polyethylene terephthalate, triacetyl cellulose, polycarbonate, and polymethyl methacrylate are preferable.

  Furthermore, known additives such as antistatic agents, ultraviolet absorbers, infrared absorbers, plasticizers, lubricants, colorants, antioxidants, flame retardants and the like are added to these organic polymers to add functions. Can also be used.

  The transparent support may be composed of one kind of the above organic polymer, may be composed of a mixture of two or more kinds or a polymer, and may be a laminate of a plurality of layers.

  Moreover, the thickness of a transparent support body can be suitably selected by the use which uses an antireflection laminated film, for example, in the case of a liquid crystal display use, 25-300 micrometers is preferable. However, the present invention is not limited to this.

  The transparent support is usually provided with a surface protective layer, but at least one surface of the support can be subjected to a surface treatment for the purpose of improving the adhesion between the surface protective layer and the support. As this surface treatment method, for example, surface roughening treatment such as sandblasting or solvent treatment, or surface oxidation treatment such as corona discharge treatment, chromic acid treatment, flame treatment, hot air treatment, ozone / ultraviolet irradiation treatment, etc. Can be mentioned.

  The hard coat layer is laminated on the transparent support, and the hard coat layer has an ultraviolet curable resin, an electron beam curable resin, or a cured product thereof as a binder, and a metal oxide. Those in which fine particles are dispersed can be used.

  For UV or electron beam curable resin compounds, the surface resistance of steel wool rubbing test, surface hardness by pencil scratch test, adhesive tape peel test, for the purpose of surface modification of the substrate on which the antireflection laminated film is installed Resin can be selected and used so as to satisfy required specifications for various properties such as adhesion and cracking properties by the minimum bending test. This compound contains a photopolymerizable prepolymer, a photopolymerizable monomer, a photopolymerization initiator, and the like.

  Examples of the photopolymerizable prepolymer include polyester acrylate, epoxy acrylate, urethane acrylate, and polyol acrylate prepolymers. These photopolymerizable prepolymers may be used alone or in combination of two or more.

  Examples of the photopolymerizable monomer include polymethylolpropane tri (meth) acrylate, hexanediol (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, Examples include dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, and neopentyl glycol di (meth) acrylate.

  The refractive index of the above-mentioned photopolymerizable monomer is around 1.5, but as a photopolymerizable monomer having a high refractive index, halogen atoms other than fluorine atoms, cyclic groups, sulfur (S), nitrogen (N) And those containing any one or more of atoms such as phosphorus (P). The cyclic group includes an aromatic group, a heterocyclic group and an aliphatic ring group. Examples of the photopolymerizable monomer having a high refractive index include bis (4-methacryloylthiophenoxy) sulfide, bisphenoxyethanol full orange acrylate, tetrabromobisphenol A diepoxy acrylate, and the like.

  By using a photopolymerizable monomer having a high refractive index in the hard coat layer, the difference between the refractive index of the hard coat layer and the refractive index of the conductive layer can be easily controlled.

  In particular, in the present invention, the hard coat layer is preferably made of a polymer mainly composed of a polyfunctional monomer having a (meth) acryloyloxy group. A polymer mainly composed of a polyfunctional monomer having a (meth) acryloyloxy group is preferable because of its excellent surface hardness, and the refractive index of the hard coat layer and the refractive index of the conductive layer are low because the refractive index of the polymer itself is low. The difference between and can be easily controlled.

  Here, the main component indicates that the polyfunctional monomer having a (meth) acryloyloxy group is contained in an amount of 10 to 100% by mass based on 100% by mass of the polymer forming the hard coat layer.

  Polymers mainly composed of a polyfunctional monomer having a (meth) acryloyloxy group include, for example, a polyfunctional photopolymerizable prepolymer having a (meth) acryloyloxy group and a polyfunctional monomer having a (meth) acryloyloxy group. It can be obtained by polymerizing a functional photopolymerizable monomer. Examples of such a photopolymerizable prepolymer include urethane acrylate, and examples of the photopolymerizable monomer include dipentaerythritol hexa (meth) acrylate, bisphenoxyethanol full orange acrylate, and the like.

  Examples of the photopolymerization initiator include acetophenones, benzoins, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones, and the like.

  Moreover, n-butylamine, triethylamine, poly-n-butylphosphine, etc. can be mixed and used for a photopolymerizable prepolymer and a photopolymerizable monomer as a photosensitizer.

In the hard coat layer, metal oxide fine particles can be further added. Type of the metal oxide fine particles is not particularly limited but may be, for example, _{SiO 2, TiO 2, Al 2} O 3, ZnO, Sb 2 O 5, ZrO 2 and the like.

  By adding metal oxide fine particles, the refractive index of the hard coat layer can be controlled, and the adhesion to the conductive layer and the hardness of the hard coat layer can be improved.

  When metal oxide fine particles are used in the hard coat layer, it is preferable to perform surface treatment on the surface of the metal oxide fine particles to increase the affinity with the organic compound as the binder. Surface treatment can be classified into physical surface treatment such as plasma discharge treatment and corona discharge treatment, and chemical surface treatment using a coupling agent. It is preferred to carry out only chemical surface treatment or both physical / chemical surface treatment.

  As the coupling agent, an organoalkoxy metal compound such as a silane coupling agent or a titanium coupling agent is preferable. For surface treatment with a coupling agent, inorganic acids (eg, sulfuric acid, hydrochloric acid, nitric acid, chromic acid, hypochlorous acid, carbonic acid, etc.) and organic acids (eg, acetic acid, polyacrylic acid, polyglutamic acid, etc.) are used as catalysts. It is preferable to use it.

  In the present invention, the hard coat layer and the conductive layer are preferably subjected to surface treatment.

  By applying the surface treatment, the surface tension of the surface of each layer can be changed, so that the adhesion between the hard coat layer and the conductive layer and between the conductive layer and the antireflection layer can be improved. Therefore, the surface hardness and scratch resistance of the antireflection laminated film can be further improved. Moreover, since the foreign material on the surface of each layer can be reduced, the antireflection laminated film which does not have a defect in appearance can be provided.

  As the surface treatment method, for example, alkali treatment, plasma treatment, laser treatment, corona treatment and the like can be performed.

  The hardness of the hard coat layer is preferably H or higher in pencil hardness in order to provide the scratch resistance necessary for the antireflection laminated film.

The antireflection layer only needs to have a refractive index smaller than that of an adjacent layer in the antireflection laminated film, and a layer made of a material used in a conventional antireflection layer may be used. it can.

  For example, when a support, a hard coat layer, a conductive layer, and an antireflection layer are laminated in this order, the antireflection layer may have a refractive index lower than that of the conductive layer. Further, when the support, the conductive layer, the hard coat layer, and the antireflection layer are laminated in this order, the antireflection layer may have a refractive index lower than that of the hard coat layer.

  As the antireflection layer, for example, a transparent thin film containing metal oxide fine particles having a low refractive index such as silicon oxide, a transparent thin film made of a fluorinated acrylic resin, or the like can be used. In particular, the antireflection layer preferably contains a silicon alkoxide represented by Chemical Formula 2 or a matrix resin containing a hydrolyzate thereof. This can further improve the strength of the laminated film.

The antireflective layer is R ″ _z Si (OR) _4−z (where R ″ represents a non-reactive functional group having an alkyl group, a fluoroalkyl group or a fluoroalkylene oxide group at the end, and z is It is an integer satisfying 1 ≦ z ≦ 3) and further containing the silicon alkoxide represented by (Chemical Formula 3) or a hydrolyzate thereof further improves the low reflectance and antifouling property of the antireflection laminated film. Therefore, it is preferable.

  Examples of the silicon alkoxide represented by Chemical Formula 3 include octadecyltrimethoxysilane, 1H, 1H, 2H, 2H-perfluorooctyltrimethoxysilane, and the like.

  The antireflection layer has n′d ′ = λ / 4 (where n ′ is the refractive index of the antireflection layer, d ′ is the thickness of the antireflection layer, λ is the wavelength of light (nm), and 500 ≦ It is preferable to satisfy (Equation 6) in order to provide a more stable and antireflection laminated film.

  The antireflection laminated film of the present invention is prepared, for example, by preparing dispersions of materials constituting the hard coat layer, the conductive layer, and the antireflection layer, respectively, and the first coating liquid, the second coating liquid, Three coating solutions can be prepared, and the first, second and third coating solutions can be applied in this order on the support.

  First, the first coating liquid is applied to the support and dried to prepare a hard coat layer. Next, a second coating solution is applied to the hard coat layer and dried to produce a conductive layer. Thereafter, a third coating solution is applied to the conductive layer and dried to produce an antireflection layer, whereby an antireflection laminated film is obtained.

  In the first coating liquid for forming the hard coat layer, there is no particular limitation on the blending order of each component. For example, metal oxide fine particles and ultraviolet or electron beam curable resin compound are added in various solvents. It can be prepared by mixing.

  The solvent is not particularly limited, but ketones such as methyl ethyl ketone, acetone and methyl isobutyl ketone, esters such as methyl acetate, ethyl acetate and butyl acetate, aromatic compounds such as toluene and xylene, diethyl ether, Mention may be made of ethers such as tetrahydrofuran, alcohols such as methanol, ethanol and isopropanol.

Moreover, well-known additives, such as an antifoamer and a leveling agent, can be mix | blended with a 1st coating liquid as needed.

  There is no restriction | limiting in particular about solid content concentration of a 1st coating liquid, The range of 10-70 mass% is preferable from surfaces, such as coating property, drying property, economical efficiency, and the range of 30-50 mass% is especially suitable. is there.

  The coating method for coating the first coating liquid on the support is not particularly limited, and a bar coating method, a knife coating method, a roll coating method, a blade coating method, a die coating method, or the like can be used.

  The thickness of the hard coat layer should be controlled by calculating the required coating amount of the first coating liquid using the solid content concentration of the first coating liquid and the density of the hard coat layer after curing. Can do.

  Alternatively, the coating layer after drying may be cured by irradiation with ultraviolet rays and electron beams in an atmosphere purged with nitrogen to form a hard coat layer with less surface damage and high surface hardness.

There is no restriction | limiting in particular about the ultraviolet irradiation apparatus used for hardening, For example, the well-known ultraviolet irradiation apparatus using a high pressure mercury lamp, a xenon lamp, a metal halide lamp, a fusion lamp etc. can be used. The amount of ultraviolet irradiation is usually about 100 to 800 mJ / cm ² . There is no restriction | limiting in particular about an electron beam irradiation apparatus, and an acceleration voltage is 50-300 kV normally.

  The hard coat layer thus obtained has excellent adhesion to the substrate on which it is placed, surface hardness, flexibility, scratch resistance, and transparency.

  As a method for forming the conductive layer, the second coating solution may be applied by various coating methods similar to those of the first coating solution so that the cured film thickness satisfies Formula 2, and then dried. it can. At this time, the refractive index of the conductive layer can be easily controlled by controlling the blending amount of the conductive fine particles in the second coating solution, and the refractive index difference between the conductive layer and the hard coat layer can be easily controlled. be able to.

  When ultraviolet rays or an electron beam curable resin compound is used in the second coating solution, ultraviolet rays or electron beam irradiation is performed after drying.

  As a method for forming the antireflection layer, the third coating solution can be applied by various coating methods similar to those of the first coating solution, followed by drying treatment. When ultraviolet rays or an electron beam curable resin compound is used in the third coating liquid, ultraviolet rays or electron beam irradiation is performed.

  The antireflection laminated film of the present invention can be applied to a polarizing plate. For example, the antireflection laminated film of the present invention in which the polarizing plate usually used for a display is coated with the first, second and third coating liquids to form a transparent support with the polarizing plate, and A display medium such as a polarizing plate including the same can be manufactured. Such a polarizing plate is excellent in all of transparency, surface hardness, scratch resistance, and antistatic properties.

  Furthermore, a display provided with said polarizing plate can be comprised. The image display system of such a display is not particularly limited, and any system such as a CRT display, a liquid crystal (LCD) display, a plasma display, an EL display, or a projection display may be used.

EXAMPLES The present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.

  An antireflection laminated film in which a transparent support, a hard coat layer, a conductive layer, and an antireflection layer were laminated in this order was produced, and the performance was evaluated according to the following method.

(Visual evaluation)
The light from the fluorescent lamp was incident on the antireflection layer side of the antireflection laminated film at a distance of 20 cm from the 20W fluorescent lamp, and visual evaluation of color unevenness and interference unevenness was performed. In the evaluation, a matte black paint was applied to the surface of the support that had not been coated, and antireflection treatment was performed. The evaluation results are shown as ◎: no color, neutral hue, ◯: slight tint, x: noticeable tint.

(Abrasion resistance)
Using steel wool (# 0000), the surface of the antireflection laminated film was rubbed 10 times with a load of 250 g, and the presence or absence of scratches was visually evaluated.

(Total light transmittance and haze value)
It measured using the image clarity measuring device [Nippon Denshoku Industries Co., Ltd. make, NDH-2000].

(Pencil hardness)
Based on JIS K5400, it evaluated with the load of 500g by the testing machine method.

(Surface resistance value)
The measurement was performed according to JIS K6911.

(Evaluation of adhesion)
The adhesion between the antireflection layer and the conductive layer was evaluated.

  The surface of the conductive layer was cut at 100 points with a 1 mm square, and then peeled from the antireflection layer side using an adhesive tape (manufactured by Nichiban Co., Ltd., 24 mm wide cello tape (registered trademark)). Evaluation was based on the residual ratio of parts. The time when all 100 points did not peel and remained in the conductive layer was defined as 100/100.

(Formation of hard coat layer)
A triacetyl cellulose film (total light transmittance: 93%, haze value: 0.1%) having a thickness of 80 μm and a refractive index of 1.49 at a wavelength of 550 nm was used as a transparent support. Moreover, the coating liquid for hard-coat layers was prepared using dipentaerythritol hexaacrylate, pentaerythritol tetraacrylate, and urethane acrylate.

  This hard coat layer coating solution was applied onto a support so as to have a dry film thickness of 5 μm, and a hard coat layer was formed by irradiating a 120 W metal halide lamp from a distance of 20 cm for 10 seconds.

  The refractive index of the hard coat layer was 1.52 at a wavelength of 550 nm, and the refractive index difference from the transparent support was 2%.

(surface treatment)
The support on which the hard coat layer is formed is immersed in a 1.5N-NaOH aqueous solution heated to 50 ° C. for 2 minutes for alkali treatment, washed with water, and then immersed in a 0.5 mass% -H 2 SO 4 aqueous solution at room temperature for 30 seconds. And neutralized, washed with water and dried.

(Formation of conductive layer)
An organosilicon compound composed of bis-trimethoxysilyl-ethane was used as a raw material, and this was hydrolyzed with 1 mol / L hydrochloric acid to obtain a hydrolyzate of an organosilicon compound composed of the resulting oligomer (hydrolyzed oligomer). 10 parts by mass of the matrix resin composed of the hydrolyzate was diluted with 90 parts by mass of isopropanol to prepare a coating liquid for the conductive layer. The coating liquid was applied to the hard coat layer subjected to the above surface treatment so that the dry film thickness was 100 nm and dried to form a conductive layer. The refractive index of the conductive layer was 1.49 at a wavelength of 550 nm, and the refractive index difference between the conductive layer and the hard coat layer was 2%.

(Formation of antireflection layer)
A silicon alkoxide represented by Chemical Formula 4 composed of tetraethoxysilane and a silicon alkoxide represented by Chemical Formula 5 composed of trimethoxysilane having a perfluorooctane group as an organic functional group are used as raw materials. A coating solution for an antireflection layer was prepared by diluting 5 parts by mass of the oligomer obtained by hydrolysis and 5 parts by mass of silica particles having a refractive index of 1.3 with 190 parts by mass of isopropanol. This coating solution was applied to the conductive layer obtained above so as to have a dry film thickness of 100 nm and dried to prepare an antireflection layer. The refractive index of the antireflection layer was 1.35 at a wavelength of 550 nm.

  As described above, an antireflection laminated film (hereinafter referred to as a laminated film) in which a transparent support, a hard coat layer, a conductive layer, and an antireflection layer were laminated in this order was obtained.

  In Example 1 (formation of conductive layer), the same procedure as in Example 1 was carried out except that 7 parts by mass of a matrix resin composed of a hydrolyzate of bis-trimethoxysilyl-ethane and 3 parts by mass of zirconium oxide fine particles were used. A laminated film was prepared in the same manner as in Example 1.

  The refractive index of the conductive layer was 1.56 at a wavelength of 550 nm, and the refractive index difference between the conductive layer and the hard coat layer was 2.6%.

  In Example 1 (formation of a conductive layer), the same procedure as in Example 1 was carried out except that 5 parts by mass of a matrix resin composed of a hydrolyzate of bis-trimethoxysilyl-ethane and 5 parts by mass of zirconium oxide fine particles were used. A laminated film was prepared in the same manner as in Example 1.

  The refractive index of the conductive layer was 1.54 at a wavelength of 550 nm, and the refractive index difference between the conductive layer and the hard coat layer was 1.3%.

<Comparative Example 1>
In Example 1 (formation of a conductive layer), an antireflection laminated film was prepared in the same manner as in Example 1 except that 10 parts by mass of silicon alkoxide made of tetraethoxysilane was used as the matrix resin.

  The refractive index of the conductive layer was 1.44 at a wavelength of 550 nm, and the refractive index difference between the conductive layer and the hard coat layer was 5.3%.

<Comparative example 2>
In Example 1 (formation of conductive layer), lamination was performed in the same manner as in Example 1 except that 7 parts by mass of an acrylic resin made of pentaerythritol triacrylate was used as the matrix resin and 3 parts by mass of zirconium oxide fine particles were used. A film was created.

  The refractive index of the conductive layer was 1.62 at a wavelength of 550 nm, and the refractive index difference from the hard coat layer was 3.9%.

  For the laminated films obtained in Examples 1 to 3 and Comparative Examples 1 and 2, visual evaluation, scratch resistance, total light transmittance and haze value, pencil hardness, surface resistance value, adhesion between the antireflection layer and the conductive layer Table 1 shows the results of the evaluation of sex. Here, the refractive index difference A indicates the refractive index difference between the hard coat layer and the conductive layer.

  As is clear from Table 1, in the examples, the surface resistance value was low and sufficient conductivity was shown. Furthermore, the haze value was low, the total light transmittance was high, that is, the transparency was good, and the evaluation results of the scratch resistance, pencil hardness, and adhesion between the antireflection layer and the conductive layer were all good.

  In Comparative Example 1 in which the conductive layer had a composition of tetraethoxysilane, a decrease in the scratch resistance and surface resistance performance was observed.

  In Comparative Example 2 in which the conductive layer was composed of an acrylic resin and zirconium oxide, scratch resistance, surface resistance, and visual evaluation performance degradation were observed.

  As is clear from the above results, in the laminated films of the examples, the hard coat performance such as scratch resistance and surface hardness can maintain sufficient performance, while at the same time exhibiting adhesion, conductivity, and high transparency. did it. Furthermore, if the film thickness of the conductive layer is within the range of Formula 2, it is possible to impart anti-reflection properties that suppress color development in the entire visible light region, and therefore, color unevenness is easily caused by a highly productive coating method. It was possible to provide an antireflection laminated film that was suppressed by the above.

  Table 1 is shown below.

  The present invention relates to various display media such as a liquid crystal display, a CRT display, a projection display, a plasma display, and an EL display, and an antireflection laminated film applied thereto.

It is sectional drawing which shows the Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Support body 2 Hard-coat layer 3 Conductive layer 4 Antireflection layer 5 Antireflection laminated film

Claims (7)

A hard coat layer, a conductive layer, and a low refractive index layer having a refractive index lower than that of the conductive layer are laminated in this order on the transparent support, and the conductive layer is (RO) ₃ Si— (CH ₂ ) _n —Si ( OR) ₃ (wherein R represents an alkyl group, and n is an integer (1 ≦ n ≦ 8)), or an organic silicon compound or a hydrolyzate thereof. .   2. The antireflection laminated film according to claim 1, wherein the conductive layer further contains inorganic fine particles having a particle diameter of 1 to 100 nm as a refractive index adjusting agent.   The antireflective laminated film according to claim 1 or 2, wherein the refractive index adjusting agent is antimony pentoxide fine particles.   The antireflective laminated film according to any one of claims 1 to 3, wherein the low refractive index layer has a matrix containing silicon alkoxide or a hydrolyzate thereof.   The antireflection laminated film according to any one of claims 1 to 4, wherein a difference between a refractive index of the hard coat layer and a refractive index of the conductive layer is within 4%.   The conductive layer satisfies nd = λ / 4 (where n is the refractive index of the layer, d is the layer thickness, λ is the wavelength of light, and is an integer satisfying 500 ≦ λ ≦ 900). The antireflection laminated film according to any one of claims 1 to 5.   A display medium comprising the antireflection laminated film according to claim 1 on the front surface of the display medium.

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